Take care of the loops reported for OpenVPN in tap mode. Also fixes the problems of tap disappearing from bridge if its a member.
Forgot to remove the problematic part from previous OpenVPN loop fix commit
Also add similar checks on rc.newwanipv6 as in the v4 version
fixing typo for GIF tunnels to work over IPv6

the call of get_interface_gatewayv6() in the creation of a GIF tunnel over IPv6 leads to a "Fatal error: Call to undefined function get_interface_gatewayv6() in /etc/inc/interfaces.inc on line 934". changeing the function call to get_interface_gateway_v6() fixed it for me on my local system.